Multilayer silver halide elements containing thiazole color couplers for yellow



3,393,041 MULTILAYER SILVER HALIDE ELEMENTS CON- TAINING THIAZOLE COLOR COUPLERS FOR YELLOW Marcel Hendrik Verbrugghe, Wilrijk-Antwerp, and Arthur Henri De Cat and Raymond Albert Roosen, Mortsel- Antwerp, Belgium, assignors to Gevaert Photo-Producten N.V., Mortsel, Belgium, a company of Belgium No Drawing. Filed July 8, 1964, Ser. No. 381,260 Claims priority, application Belgium, July 9, 1963, Patent 634,670 7 Claims. (Cl. 96-74) ABSTRACT OF THE DISCLOSURE Improved color couplers for use primarily in photographic multilayer color materials are described. The color couplers are 2-(aroylacetamido)-thiazoles having at least one sulphonic acid group on the aroyl moiety. The color couplers when employed in photographic materials exhibit an unusually high degree of stability to the action of light, heat and humidity.

This invention is concerned with the production of photographic color images, with the color couplers for yellow utilised therein and with photographic materials comprising such color couplers.

With respect to the production of a photographic color image in a light-sensitive silver halide emulsion layer it is known that the exposed silver halide is developed to a silver image with the aid of an aromatic primary amino compound in the presence of a color coupler by which at the areas corresponding with the silver image a dye is formed by reaction with the oxidised developing substance.

In subtractive color photography use is made currently of a light-sensitive photographic color material comprising a silver halide emulsion layer sensitised to red light, a silver halide emulsion layer sensitised to green light and a silver halide emulsion layer sensitised to blue light, in which emulsion layers are formed a cyan, a magenta, and a yellow dye image by using appropriate color couplers during the color development.

It is known that color couplers must satisfy various requirements according to the method by which the color material is manufactured and the purpose for which it is used.

For manufacturing an appropriate photographic multilayer color material containing color couplers for each color separation image in the differently optically sensitised silver halide emulsion layers, the color couplers ought to be present in the hydrophilic silver halide emulsion layers in non-migratory form. This object can be accomplished e.g. by the use of a, sufliciently water-soluble color coupler comprising an organic radical sufiiciently large to prevent the color coupler from diffusing in the hydrophilic silver halide emulsion layer, or by the utilisation of a lipophilic color coupler, which in dissolved state in a high- -boiling organic solvent is dispersed in the silver halide emulsion layer.

United States Patent 3,393,041 Patented July 16, 1968 'ice In the production of color images, more particularly of positive color images e.g. on a paper support, it is important to dispose of color couplers, which on color development form dyes that are quite resistant to the action of light, humidity, and heat.

A new class of color couplers for yellow of the ketomethylene type, more particularly 2-(aroylacetamido)- thiazole derivatives has been found now. These color couplers display a high activity during color development and form yellow dyes possessing a favorable resistance to humidity and heat.

These 2-(aroylacetamido)-thiazole derivatives are characterised by the presence of at least one group solubilising in water, more particularly a sulphonic acid group in the aroyl part of the molecule. The sulphonic acid gr0up(s) can be implanted directly in the aromatic nucleus of the aroyl group or can be present in an aromatic nucleus, which is linked to the aromatic nucleus of the aroyl group by means of a bivalent radical.

Suitable color couplers for yellow according to the present invention are color couplers in which at least one sulphonic acid group is implanted directly in the aromatic nucleus of the aroyl group, and which comply with the following general formula:

Br I

wherein R represents a sulphonic acid group or its salt form,

R represents hydrogen, halogen, alkoxy, a sulphonic acid group or its salt form, or a group rendering fast to diffusion such as a n-hexadecyloxy group,

R represents hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, preferably a group rendering fast to diffusion such as i.e. the group XR, in which X represents a chemical bond, oxygen or sulphur and R an acyclic aliphatic hydrocarbon rest with 5 to 20 carbon atoms,

R represents hydrogen, alkyl, substituted alkyl, aryl, a substituted aryl radical with substituents such as alkoxy, halogen, alkylsulphonyl, a group rendering fast to diffusion such as a n-hexadecyloxy group, a n-hexadecylmercapto group or a pentadecyl group, and

R and R together may represent the atoms necessary for completing an aromatic ring system, which is either or not further substituted.

Suitable color couplers for yellow according to the present invention are color couplers, in which at least one sulphonic acid group in the aroyl part of the molecule is implanted in an aromatic nucleus linked to the aromatic nucleus of the aroyl group by means of a bivalent radical, and which comply with the following general Formula II F-Ra wherein R R and R have the same significance as given in Formula I,

R' represents an either or not further substituted sulphonated aromatic radical such as e.g. a sulphonated phenyl group, and

Y represents a bivalent radical such as a CONH- group, a SO NH group, or a NHCONH group.

The preparation of the color couplers according to the general Formula I is illustrated by the following reaction scheme:

3 -o 01-110 0 o c2115 NHZW nah wherein R R or R may contain a group rendering fast to diffusion.

Structural formulae of color couplers according to the general Formula I are the following:

(1) SOzNa s n W IMO-(OHzhs-O-Q- N HaC O 5 (5) I SO Na SOgNa SOQNa H TNII-GOA'JHa-OO- i N SO Na 1 PREPARATION OF fl-KETOESTER DERIVATIVES DROLYSIS TO SULPHONIC ACID DERIVATIVES (a) Preparation of Z-aminothiazole derivatives (mentioned in Table 1, col. 2)

iZ-AMINO- l- [4-(n-HEXADECYLOXYPHENYL) THIAZOLFJ An amount of p-n-hexadecyloxyphenacyl bromide is dissolved in isopropanol and an equivalent amount of thiourea is added to this solution. The reaction mixture is refluxed for 30 min. and a bulky precipitate of aminothiazole hydrobromide is formed. The base is set free therefrom by treatment with concentrated ammonium hydroxide. A white crystalline product is obtained after separating the precipitate, rinsing with water and recrystallising from ethanol. Melting point: 109 C.

2-AMINO-4-METHYL-5-TETRADECYLTHIAZOLE To an amount of methyl pentadecyl ketone dissolved in carbon tetrachloride is added dropwise an equivalent amount of bromine at 15-20 C. while stirring. The bromine immediately reacts and a vigorous development of hydrobromic acid takes place. The mixture is stirred for 30 min. yet and the solvent is then distilled off in vacuo. The residue is dissolved in ethanol and an equivalent amount of thiourea is added. Subsequently the reaction mixture is heated for 30 min. at reflux temperature and then neutralised with ammonium hydroxide. The mixture is then poured out into ice water. The resulting precipitate is dried and recrystallised from n-hexane. A white finely crystalline product is obtained. Melting point: 57 C.

2-AMINO-4-PHENYL-5-TETRADECYLTHIAZOLE To an amount of palmitoylbenzene (F. Krafft, Ber. 19 (1886) 2983) dissolved in carbon tetrachloride is added dropwise an equivalent amount of bromine whilst stirring. The brown color of bromine immediately disappears and a vigorous development of hydrobromic acid takes place. The mixture is stirred for another 30 min. and subsequent ly the solvent is distilled off in vacuo. The residue is recrystallised from ethanol. White crystal leaflets of a-bromopalmitoylbenzene are obtained. Melting point: 47-48 C.

To an amount of this compound dissolved in ethanol is added an equivalent amount of thiourea and the resulting reaction mixture is heated at boiling temperature for 1 h. After neutralisation of the reaction mixture with ammonium hydroxide and pouring out in water, the resulting precipitate is rinsed with water and dried. After recrystallisation frorn n-hexane the 2-amino-4-phenyl-5- tetradecylthiazole is obtained in the form of a white crystalline product. Melting point: 68 C.

2-AMINO-4- (4-METHOXYPHENYL) -5-TETRA- DECYLTHIAZOLE This compound is synthesised in a similar way as described in the foregoing preparation starting, however, with 4-palmitoyl anisol.

4-palmitoyl anisol is prepared by Friedel-Crafts acylation with palmitoyl chloride as described in F. Kralft, Ber. 19 (1886) 2983. After recrystallisation from ethanol 21 white crystalline product is obtained. Melting point: 70 C.

4-(a-bromopalmitoyl)-anisol is obtained in the form of white crystalline leaflets after recrystallisation from ethanol. Melting point: 79-80 C.

2 amino 4 (4 methoxyphenyl) 5 tetradecylthiazole is obtained as a white crystalline product after recrystallisation from n-hexane. Melting point: 79 C.

2-AMIN'O-4- a-CARBETHOXYHEPTADECYL) THIAZOLE First the a-n-hexadecyl acetylacetic acid ethyl ester is prepared analogously to the methyl ester (I. Gunther Ber. 71 B (1938) 2634) starting with acetylacetic acid ethyl ester, n-hexadecyl bromide and sodium ethylate in ethanol. A colourless viscous oil is obtained. Boiling point: 174- 175 C. (0.5 mm. Hg).

To a solution of this a-n-hexadecyl acetylacetic acid ethyl ester in carbon tetrachloride is added dropwise an equivalent amount of bromide. This solution is kept at room temperature for 24 h. By caralysis of the formed hydrobromic acid the initially u-bromo-substituted Ot-Ilhexadecyl acetylacetic acid ethyl ester is converted into the -bromo derivative. The solvent is then distilled off in vacuo and the residue is dissolved in ethanol. Subsequently an equivalent amount of thiourea is added and the reaction mixture is heated at boiling temperature for 15 min. The base is set free from the resulting aminothiazole hydrobromide by treatment with ammonium hydroxide. After pouring out in water, the resulting precipitate is dried and recrystallised from n-hexane. The 2-amino-4-(a-carbethoxyheptadecyl)-thiazole is obtained in the form of white fine crystal needles. Melting point: C.

Z-AMINO-ES-mHEXADECYL MERCAPTOTHIAZOLE To a solution of 2-amino-5-bromothiazole hydrobromide (J. P. English, I. Am. Chem. Soc. 68 (1946) 456) in a mixture of ethanol and water (10:1) is dropwise added an equivalent amount of n-hexadecylmercaptane and a double amount of potassium hydroxide dissolved in ethanol. The reaction mixture is heated to boiling temperature and stirred at this temperature for 4 h. The formed potassium bromide is filtered off. When cooling a precipitate is formed in the filtrate. This precipitate is first recrystallised from dichloroethane and secondly from methanol. A yellowish crystalline product is obtained. Melting point: 98 C.

2-aminothiazole 2-amino-4-phenylthiazole (Dodson, King J.A.C.S. 67,

Z-aminobenzothiazole (b) Preparation of 2-benzoylacetamido)-thiazole derivatives.-Reaction step (a) GENERAL PROCESS 0.1 mole of amino derivative, 0.1 mole of B-ketoester derivative and 0.2 g. of anhydrous sodium acetate are added to 100 ml. of anhydrous xylene. The reaction mixture is refluxed and a mixture of xylene and the formed ethanol is distilled off slowly till the temperature reaches 138 C., which lasts approximately one hour.

Subsequently the remaining xylene is distilled off in vacuo. To the residue 200 ml. of hexane are added and the resulting precipitate is filtered off and recrystallised from a suited solvent.

The results of condensations of Z-aminothiazole derivatives with fluorosulphonyl-substituted B-ketoester derivatives are listed in Table 1 (col. 3 and 4).

(c) Alkaline hydrolysis to sulphonic acid derivatives of the fiuorosulphonyl-substituted benzoylacetanilides.- Reaction step (b) GENERAL PROCESS 0.1 mole of sulphonylfiuoride derivative is heated to boiling temperature with 400 ml. of acetone. Whilst stirring 60 ml. of 5 N sodium hydroxide are added slowly, thus causing an exothermic reaction. The reaction mixture is heated at boiling temperature for 30 min. whilst stirring. Subsequently the mixture is acidified with acetic acid and next cooled to room temperature. The resulting precipitate is washed with water and recrystallised from a suited solvent.

The results of these alkaline hydrolyses are listed in Table 1 (col. 5 and 6). Col. 6 refers to the number of the structural formula of the prepared color coupler for yellow, whereas col. 7 indicates the absorption maximum of the azomethine dye obtained when developing with N-diethyl-p phenylene diamine.

The following reaction scheme ilustrates the synthesis of these compounds:

is carried out in dioxan at 80 C. under a hydrogen pressure of 42 kg. per sq. cm. When the calculated amount J S PIIIJOOCMHHS s FSO -WNH ooornooNnj D wherein:

Z represents a COCl group or a NCO group, and W stands for a C( group or a -NHCO- group.

(A) Utilized starting products (a) 2-[11-3 '-amin obenzoyl acetyl] -amino-4- p-n-hexadecyloxyphenyl) -thiazole lO ocmllas The synthesis of 2-[ot-(3'-nitrobenzoyl)-acety1]amino-4- (p-n-hexadecyloxyphenyl)-thiazole (reaction step (a)) is similar to that of the analogous condensation products described in the copending patent application for Color 'Couplers for Color Photography. A yellow crystalline product is obtained by condensation of 41.6 g. of Z-amino- 4-(p-n hexadecyloxyphenyl)-thiazole with 23.7 g. of 3- nitrobenzoyl acetic acid ethyl ester and by recrystallisation from dioXan. Melting point: 135 C.

The resulting nitro derivative is then converted into the amine by hydrogenation in the presence of Raney nickel as a catalyst (reaction step (b')). The reduction of hydrogen is consumed, the catalyst is filtered off. On cooling a precipitate is formed in the filtrate. This pre- 0 cipitate is collected and washed with dichloroethane. The

2-a-(3'-aminobenzoyl)-acety1amino 4 (p-n-hexadecyloXyphenyl)-thiaz0le is obtained in the form of a white to brownish crystalline product. Melting point: 157- 158 C.

(b) 3-fluorosulphonyl benzoyl chloride is prepared as described in the above-mentioned Belgian patent specification.

(c)- 3-fluorosulphonyl phenyl isocyanate is prepared as described in the above-mentioned Belgian patent specification.

(B) Reaction of 2-m-(3'-aminobenzoyl)-acety1amino-4- (p n hexadecyloxyphenyl) thiazole with fiuorosulphonyl compounds.-Reaction step (c) 1 1 1 2 zole derivative and an equivalent amount of 3-fluorosula blue-sensitive silver halide emulsion layer with a color phonyl phenyl isocyanate a yellowish crystalline product coupler for yellow. The support of this multilayer mais obtained after recrystallisation from acetonitrile. Meltterial may consist of paper, glass, cellulose nitrate, a celing point: 180 C. lulose ester such as cellulose triacetate, polyester, poly- 5 styrene or another synthetic or natural resin.

A yellow filter layer generally comprising colloidal silver dispersed in gelatin, is provided usually between (C) Alkaline hydrolysis to sulphonic acid derivatives.- Reaction step (d) The alkaline hydrolysis of the sulphonyl fluoride deriv' the silver halide emulsion layer containing a color couatives P p according reaction p is Carried pler for yellow and the green-sensitised silver halide out as stated under 2(0). The results of specific alkaline 0 emulsion layer,

hydrolysis are listed in Table 2. As sulphonyl fluoride derivatives the color couplers for TAB LE 2 sulphonyl fluoride derivative FSOQ XNH COCH2CONH Sulphome acid derlvatwe (SO Na) Number of the Absorption maximum of the structural azomethine dye obtained Recrystallisation medium formula of the when developing with color coupler N-diethyl-p-phenylcne diamine, my

X=CO Ethylene glycol mono- 11 465 methyl ether/water. NHCO- do 12 460 The color couplers need not necessarily be separated yellow according to the present invention may be applied in the form of sulphonic acid derivatives before their adin so-called droplet emulsions (cf. US. patent specificadition to the silver halide emulsion. The sulphonic acid tion 2,304,940). derivatives formed in situ from the sulphonyl fluoride For the production of photographic color images acderiva-tives by dissolving the latter derivatives in alkali cording to the present invention an exposed silver halide may be added as such to the emulsion. Preferably 1 mole emulsion layer is developed with an aromatic primary of sulphonyl fluoride derivative is dissolved therefor in amino developing substance in the presence of a color an aqueous solution of 3 mole of sodium hydroxide and coupler for yellow according to the present invention. after adjustment of the pH value in accordance with the All color developing agents capable of forming azopH of the emulsion applied the resulting clear solution methine dyes can be utilised as developers. Aromatic iS \added in the form Of a 5 f0 10% aqueous solution l0 primary amino compounds such as p-phenylene diamine the silver halide emulsion. and derivatives such as N-diethyl-p-phenylene diamine, During the preparation of the lightsensitive color ma- N,N di th l-N'-sul hometh l- -phenylen diamine and terial the non-migratory color couplers for yellow accord- N,N-diethy1-N'-carboxymethyl-p-phenylene diamine are ing to the above-mentioned general formulae are mixed commonly d,

homogeneously in dlSSOlVCd state With the light-sensitive On 0101- development with aromatic primary amines silver halide emulsion preferably immediately before the h as N-diethyl-p-phenylene di i th color couplers coating the emulsion- This y as Well be added for yellow according to the present invention form yelthe composition of a water-permeable non-light-sensitive 1 d h i an b ti spectrum hi h makes layer, which is in direct contact With the, light-sensitive these colgr couplers apt to be used in positive masilver halide emulsion layer or they may be incorporated i l b i maximum from 450 to 465 into a non-light-sensitive layer which is separated from Th color couplers ma ifest a hi h ti it d i the light-Sensitive layer y a Water-permeable nOn-lightthe development, i.e. they furnish color images having sensitive layer. The silver halide emulsion contains the i h 1 d i ual Colloids such as gelatin, P y y 31001101), The dyes formed on color development show good lodion or other suitable natural or synthetic colloids. resistance to heat and humidity This iS illustrated by The photogl'aphle emulsloll y further qq f usual comparative tests, the description and results of which ingredients such as hardeners, chemical sensrtismg agents, will be given h i ft Optical sellsitisl ll g agents, p s development The resistance to humidity and heat of the dyes is deeelefaml's, stablllslng agents and WemPg a terrnined from the decrease in density of a developed e 00101 couplers for Yellow desenbed F f P Wedge print after having stored said wedge print for a invention are added usually to a blue-sensitive silver certain time 5 days) at a ifi temperature (e'g, halide emulsion. According to a common procedure 1n 5 Q) and a relative humidity (6% 87%) While being the art this silver halide emulsion is coated as the last protected f light c0101 eoupler'eontamlng layer of a PhotograPhlc The following table clearly illustrates the resistance to layer color material. Such photographic multilayer color humidity and heat f dyes f r d on 1 developmaterial usually consists in the given sequence of a ment by reaction of the resulting oxidation product of port, a red-sensitised silver halide emusion layer with a N-dithy1-p-phenylcne diamine with color Couplers color coupler for cyan, a green-sensitised silver halide cording to the present invention and of a color coupler emulsion layer with a color coupler for magenta and described in the British patent specification 873,125.

Maximum The percentage Maximum density after decrease of density 6 days at maximum Formula of the color coupler at the 35 C. and a density after beginning relative days at 35 C. of the test humidity and at a relative of 87% humidity of 87% S COCH CONH W 1.2 1.2 0

N-OOCmHsa S NaOOzS CONH COCHzCONH l 1.2 1.2 o NC O C 16H C O O CH; 1. 2 0. 9

(Color coupler for yellow according to the British Patent Specification 873,125)

The higher activity during color development of color couplers according to the present invention is proved by a comparative test in which a similar amount of color coupler for yellow is added to two identical silver halide emulsions, i.e. a color coupler A according to the present invention and a color coupler B containing no thiazole group, more particularly a color coupler for yellow stated in the British patent specification 783,887.

These silver halide emulsions are coated, exposed and developed in identical conditions. The relative maximum density of the developed emulsion strips comprising the color coupler A and B respectively listed in the following table.

loid layer adjacent to said light-sensitive silver halide emulsion layer a color coupler for yellow which is a 2-(aroylacetamido)-thiazole, wherein at least one sulfonic acid group is present in the aroyl part of the molecule.

3. Photographic multilayer color material comprising three silver halide emulsion layers which have different optical sensitivities, and containing in nonmigratory form in a member selected from the blue-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable colloid layer adjacent thereto a color coupler for yellow which is a 2-(aroylacetamido)-thiazole wherein at least one sulfonic acid group is present in the aroyl part of the molecule.

As to the structure of the color couplers according to the present invention, it should be noticed yet that when using the expression sulphonic acid group or sulphonic acid substituent the acid form as well as the salt form of this group or substituent are meant and that whenever the color couplers are used in the salt form they preferably contain an alkali metal cation, an ammonium group or an amine salt group as a cation.

We claim:

1. Photographic material comprising a silver halide emulsion layer and a color coupler for yellow which is a 2-(aroylacetamido)-thiazole wherein at least one sulfonic acid group is present in the aroyl part of the molecule.

2. Photographic multilayer color material containing in non-migratory form in a member selected from the group consisting of a light-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable col- 4. Photographic multi-layer color material containing in non-migratory form in a member selected from the group consisting of a light-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable colloid layer adjacent to said light-sensitive silver halide emulsion layer a color coupler for yellow having the general for- NR-i R represents a member selected from the group consisting of a hydrogen atom, a halogen atom, a methoxy group, a sulfonic acid group, a sulfonic acid salt group,

and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

further R and R together may also represent the atoms necessary for completing an aromatic ring system.

5. Photographic multi-layer color material containing in non-migratory form in a member selected from the group consisting of a light-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable colloid layer adjacent to said light-sensitive silver halide emulsion layer a color coupler for yellow having the general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, a halogen atom, a methoxy group, a sulfonic acid group, a sulfonic acid salt group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

Y represent a bivalent radical, and

R' represents a sulphonated aromatic radical.

-6. Photographic multi-layer color material comprising three silver halide emulsion layers Which have different optical sensitivities, and containing in non-migratory form in a member selected from the blue-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable colloid layer adjacent thereto a color coupler for yellow having the general formula:

wherein R represents a member selected from the group consisting of a sulfonic acid group and a salt form thereof,

R represents a member selected from the group consisting of a hydrogen atom, a halogen atom, a methoxy group, a sulfonic acid group, a sulfonic acid salt group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

further R and R together may also represent the atoms necessary for completing an aromatic ring system. 7. Photographic m-ulti-layer color mate-rial comprising three silver halide emulsion layers which have different optical sensitivities, and containing in non-migratory form in a member selected from the blue-sensitive silver halide emulsion layer and a non-light-sensitive water-permeable colloid layer adjacent thereto a color coupler for yellow having the general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, a halogen atom, a methoxy group, a sulfonic acid group, a sulfonic acid salt group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, and a group rendering fast to diffusion,

Y represents a bivalent radical, and

R represents a sulphonated aromatic radical.

References Cited UNITED STATES PATENTS 2,895,825 7/1959 Pelz et al 9656.6 3,008,827 11/1961 Jaeken 96-100 3,056,674 10/1962 Hoffstadt et a1. 96-100 2,863,874 12/1958 Gregory 260306.8 3,124,588 3/1964 Reisner 260-3068 2,933,391 4/1960 Feniak et a1. 96100 2,983,608 5/1961 Beavers 96100 OTHER REFERENCES Glafkid'es: Photographic Chemistry, vol. 2, page 606, Fountain Press, London (1960).

I. TRAVIS BROWN, Primary Examiner.

NORMAN G. TORCHIN, Examiner. 

